view libutil/hexdigits.c @ 47:b0cf75d0bb2d

doc/Serial-SIM-readers article written
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 21 Mar 2021 04:32:18 +0000
parents 34bbb0585cab
children
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/*
 * This module contains elementary functions for working with hex digits.
 */

decode_hex_digit(c)
{
	if (c >= '0' && c <= '9')
		return(c - '0');
	if (c >= 'A' && c <= 'F')
		return(c - 'A' + 10);
	if (c >= 'a' && c <= 'f')
		return(c - 'a' + 10);
	return(-1);
}

encode_hex_digit(d)
	unsigned d;
{
	if (d <= 9)
		return(d + '0');
	else
		return(d - 10 + 'A');
}